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CVE-2021-34556

5.5 medium SSVC exploitation: none Modified
NVD · CVE.org

In the Linux kernel through 5.13.7, an unprivileged BPF program can obtain sensitive information from kernel memory via a Speculative Store Bypass side-channel attack because the protection mechanism neglects the possibility of uninitialized memory locations on the BPF stack.

Fix

Patch, vendor advisory and mitigation references on NVD 4

Every line above is quoted from NVD, CISA, Microsoft, the vendor's own advisory or DISA; nothing is generated.

Change history 1

  1. First seenCVSS 5.5 · linux, fedoraproject, debianNVD modified 2026-10-08 21:17

Affected (CPE criteria) 4

  • cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
  • cpe:2.3:o:fedoraproject:fedora:33:*:*:*:*:*:*:*
  • cpe:2.3:o:fedoraproject:fedora:34:*:*:*:*:*:*:*
  • cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:*

References 12